The present invention relates to improved method for producing a wood-type golf club head, and more particularly relates to improvement in production of a wood-type golf club head including a shell made of fiber reinforced plastics.
One example of such a wood-type golf club head is disclosed in Japanese Patent Publication Sho. 51-21436. This golf head club includes a shell made of fiber reinforced plastics and a synthetic resin foam core filled in the cavity of the shell. Production of such a golf club head, however, is conventionally accompanied with various operational difficulties caused by the complicated configuration of club heads in general.
As well known, the cavity of a mould used for shaping the shell of a club head usually has a fixed dimension adapted for that club head. Variations in size and/or total amount of materials making up an unfinished club head and/or operational variance in combination of these materials tend to cause insufficient pressure to act on the fiber reinforced material filling the cavity of a mould at heat pressing, and such insufficient and unstable pressure application is liable to cause poor inter-layer connection in a laminated fiber reinforced plastics construction and increased generation of air voids at borders of the layers and/or in the surface area of the obtained club head, thereby degrading the commercial value of the products.
In order to avoid such disadvantages arising from pressure deficienty at heat pressing in a mould, use of a rubber air bag in a mould is proposed. That is, the rubber air bag is first covered with fiber reinforced plastic material and, after placing in the cavity of the mould, pressurized fluid such as air is introduced into the bag which inflates to press the fiber reinforced plastic material against the wall of the cavity of mould. In this case, however, it is impossible to provide the fiber reinforced plastic covering with a configuration close to the shape of the mould cavity wall before introduction of the pressurized fluid into the rubber air bag and, as a consequence, the fiber reinforced plastic covering can hardly follow the mould cavity wall with complete fidelity when the latter is relatively complicated in shape.